A Treatise of Human Nature · David Hume
GENERAL INTRODUCTION TO VOL. I.
Undoubtedly, if Hume allowed us to drop the distinction between feeling as it might be for a merely feeling consciousness, and feeling as it is for a thinking consciousness, the objection to his speaking of feeling in those terms, in which it must be spoken of if extension is to be a feeling, would disappear; but so, likewise, would the objection to speaking of thought as constitutive of reality. To appreciate his view we must take feeling not as we really know it--for we cannot know it except under those conditions of self-consciousness, the logical categories, which in his attempt to get at feeling, pure and simple, Hume is consistent enough to exclude--but as it becomes upon exclusion of all determination by objects which Hume reckons fictitious. What it would thus become _positively_ we of course cannot say, for of the unknowable nothing can be said; but we can decide _negatively_ what it cannot be. Can that in any case be said of it, which must be said of it if a feeling may be extended, and if extension is a feeling? Can it be such a quality of an object, so consisting of parts, and such a relation, as we have found that Hume takes it to be in his account of the perception of this table? ... which it can only mean as the result of certain ‘fictions’.
240. After having taken leave throughout the earlier part of the ‘Treatise on Human Nature’ to speak in the ordinary way of objects and their qualities--and otherwise of course he could not have spoken at all--in the fourth book he seems for the first time to become aware that his doctrine did not authorise such language. To perceive qualities of an object is to be conscious of relation between a subject and object, of which neither perishes with the moment of perception. Such consciousness is self-consciousness, and cannot be reduced to any natural observable event, since it is consciousness of that of which we cannot say ‘Lo, here,’ or ‘Lo, there,’ ‘it is now but was not then,’ or ‘it was then but is not now.’ It is therefore something which the spirit of the Lockeian philosophy cannot assimilate, and which Hume, as the most consistent exponent of that spirit, most consistently tried to get rid of. The subject as self, the object as body, he professes to reduce to figures of speech, to be accounted for as the result of certain ‘propensities to feign:’ nor will he allow that any impression or idea (and impressions and ideas with him, be it remembered, exhaust our consciousness) carries with it a reference to an object other than itself, any more than do pleasure or pain to which ‘in their nature’ all perceptions correspond. [1] He cannot, indeed, avoid speaking of the consciousness thus reduced to the level of simple pain and pleasure, as being that which in fact it can only be when determined by relation to a self-conscious subject, _i.e._ as itself an object; but he is so far faithful in his attempt to avoid such determination, that he does not reckon the object more permanent than the impression. It, too, is a ‘perishing existence.’ As the impression disappears with a ‘turn of the eye in its socket,’ so does the object, which really is the impression, and cannot appear other than it is any more than a feeling can be felt to be what it is not. [2]
How much of the perception, then, will survive? Can any feelings, strictly speaking, be cotemporaneous? Those received through different senses, as Hume is careful to show, may be; _e.g._ the smell, taste, and colour of a fruit. [1] In regard to them, therefore, we may waive the difficulty, How can feelings successive to each other be yet co-existent qualities? but only to find ourselves in another as to what the object may be of which the cotemporaneous feelings are qualities. It cannot, according to Hume, be other than one or all of the cotemporaneous feelings. Is, then, the taste of an apple a quality of its colour or of its smell, or of colour, smell, and taste put together? It will not help us to speak of the several feelings as qualities of the ‘total impression;’ for the ‘total impression’ either merely means the several feelings put together, or else covertly implies just that reference to an object other than these, which Hume expressly excludes. [1] ‘The taste and smell of any fruit are inseparable from its other qualities of colour and tangibility, and ... ’tis certain they are always co-existent. Nor are they only co-existent in general, but also cotemporary in their appearance in the mind.’ p. 521. (Contrast p. 370, where existence and appearance are identified.) [Book I, part IV., sec. V. and part II, sec. IV.]
The thing will have ceased before the quality begins to be. 242. In fact, however, when he speaks of the feeling, which is called extension, as a quality of the feeling, which is called sight, of the table, he has not even the excuse that he might have had if the feelings in question, being of different senses, might be cotemporary. According to him they are feelings of the same sense. The extension of the table he took to be a datum of sight just as properly as its colour; yet he cannot call it the same as colour, but only ‘a quality of the coloured object.’ As the ‘coloured object,’ however, apart from ‘propensities to feign,’ can, according to him, be no other than the feeling of colour, his doctrine can only mean that, colour and extension being feelings of the same sense, the latter is a quality of the former. Is this any more possible than that red should be a quality of blue, or a sour taste of a bitter one? Must not the two feelings be successive, however closely successive, so that the one which is object will have disappeared before the other, which is to be its quality, will have occurred? [1] [1] It should be needless to point out that by taking extension to be a quality of ‘tangibility’ or muscular effort we merely change the difficulty. The question as to its relation to such feelings will be simply a repetition of that, put in the text, as to its relation to the feeling of colour.
Hume equivocates by putting ‘coloured points’ for colour. 243. If we look to the detailed account which Hume gives of the relation between extension and colour, we find that he avoids the appearance of making one feeling a quality of another, by in fact substituting for colour a superficies of coloured points, in which it is very easy to find extension as a quality because it already is extension as an object. To speak of extension, though a feeling, as made up of parts is just as legitimate or illegitimate as to speak of the feeling of colour being made up of coloured points. The legitimacy of this once admitted, there remains, indeed, a logical question as to how it is that a quality should be spoken of in terms that seem proper to a substance--as is done when it is said to consist of parts--and yet, again, should be pronounced a relation of these parts; but to one who professed to merge all logical distinctions in the indifference of simple feeling, such a question could have no recognised meaning. It is, then, upon the question whether, according to Hume’s doctrine of perception, the perception of an object made up of coloured points may be used interchangeably with the perception of colour, that the consistency of his doctrine of extension must finally be tried.
244. The detailed account is to the following effect:--‘Upon opening my eyes and turning them to the surrounding objects, I perceive many visible bodies; and upon shutting them again and considering the distance betwixt these bodies, I acquire the idea of extension.’ From what impression, Hume proceeds to ask, is this idea derived? ‘Internal impressions’ being excluded, ‘there remain nothing but the senses which can convey to us this original impression.’ ... ‘The table before me is alone sufficient by its view to give me the idea of extension. This idea, then, is borrowed from and represents some impression which this moment appears to the senses. But my senses convey to me only the impressions of coloured points, disposed in a certain manner. ... We may conclude that the idea of extension is nothing but a copy of these coloured points and of the manner of their appearance.’ [1] [1] Pp. 340 and 341. [Book I, part II., sec. III.] Can a ‘disposition of coloured points’ be an impression?
245. If the first sentence of the above had been found by Hume in an author whom he was criticising, he would scarcely have been slow to pronounce it tautological. As it stands, it simply tells us that having seen things extended we consider their extension, and upon considering it acquire an idea of it. It is a fair sample enough of those ‘natural histories’ of the soul in vogue among us, which by the help of a varied nomenclature seem able to explain a supposed later state of consciousness as the result of a supposed earlier one, because the terms in which the earlier is described in effect assume the later. It may be said, however, that it is only by a misinterpretation of a carelessly written sentence that Hume can be represented as deriving the idea of extension from the consideration of distance; that, as the sequel shows, he regarded the ‘consideration’ and the ‘idea’ in question as equivalent, and derived from the same impression of sense. It is undoubtedly upon his account of this impression that his doctrine of extension depends. It is described as ‘an impression of coloured points disposed in a certain manner.’
To it the idea of extension is related simply as a copy; which, we have seen, properly means with Hume, as a feeling in a less lively stage is related to the same feeling in a more lively stage. It is itself, we must note, the _impression_ of extension; and it is an impression of sense, about which, accordingly, no further question can properly be raised. Hume, indeed, allows himself to speak as if it were included in a ‘perception of visible bodies’ other than itself; just as in the passage from the fourth book previously examined, he speaks as if the perception, called extension, were a quality of some other perception. This we must regard as an exercise of the privilege which he claims of ‘speaking with the vulgar while he thought with the learned;’ since, according to him, ‘visible body,’ in any other sense than that of the impression of coloured points, is properly a name for a ‘propensity to feign’ resulting from a process posterior to all impressions of sense. The question remains whether, in speaking of an impression as one of ‘coloured points disposed in a certain manner,’ he is not introducing a ‘fiction of thought’ into the impression just as much as in calling it a ‘perception of body.’ The points must be themselves impressions, and therefore not co-existent.
246. An impression, we know, can, according to Hume, never be _of_ an object in the sense of involving a reference to anything other than itself. When one is said, then, to be _of_ coloured points, &c., this can only mean that itself _is_, or consists of, such points. Thus the question we have to answer is only a more definite form of the one previously put, Can a feeling consist of parts? In answering it we must remember that the parts, here supposed to be coloured points, must, according to Hume’s doctrine, be themselves impressions or they are nothing. Consistently with this he speaks of extension as ‘a compound impression, consisting of parts or lesser impressions, that are indivisible to the eye or feeling, and may be called impressions of atoms or corpuscles, endowed with colour and solidity.’ [1] Now, unless we suppose that a multitude of feelings of one and the same sense can be present together, these ‘lesser impressions’ must follow each other and precede the ‘compound impression.’ That is to say, none of the parts of which extension consists will be in existence at the same time, and all will have ceased to exist before extension itself comes into being.
Can we, then, adopt the alternative supposition that a multitude of feelings of one and the same sense can be present together? In answering this question according to Hume’s premisses we may not help ourselves by saying that in a case of vision there really are impressions on different parts of the retina. To say that it _really_ is so, is to say that it is so for the _thinking_ consciousness--for a consciousness that distinguishes between what it feels and what it knows. To a man, as simply seeing and while he sees, his sight is not an impression on the retina at all, much less a combination of impressions on different parts of the retina. It is so for him only as thinking on the organs of his sight; or, if we like, as ‘seeing’ them in another, but ‘seeing’ them in a way determined by sundry suppositions (bodies, rays, and the like) which are not feelings, and therefore with Hume not possible ‘perceptions,’ at all. But it is the impression of sight, as it would be for one simply seeing and while he sees, undetermined by reference to anything other than itself, whether subject or object--an impression as it would be for a merely feeling consciousness or (in Hume’s language) ‘on the same footing with pain and pleasure’--that we have to do with when, from Hume’s point of view, we ask whether a multitude of such impressions can be present at once, _i.e._ as one impression.
To convict so skilful a writer of a contradiction in terms can never be an easy task. He does not in so many words tell us that all impressions of sight must be successive, but he does tell us that ‘the impressions of touch,’ which, indifferently with those of sight, he holds to constitute the compound impression of extension, ‘change every moment upon us.’ [2] And in the immediate sequel of the passage where he has made out extension to be a compound of co-existent impressions, he derives the idea of time ‘from the succession of our perceptions _of every kind_, ideas as well as impressions, and impressions of reflection as well as of sensation.’ The parts of time, he goes on to say, cannot be co-existent; and, since ‘time itself is nothing but different ideas and impressions succeeding each other,’ these parts, we must conclude, are those ‘perceptions of every kind’ from which the idea of time is derived. [3] It is only, in fact, by availing himself of the distinction, which he yet expressly rejects, between the impression and its object, that he disguises the contradiction in terms of first pronouncing certain impressions, as parts of space, co-existent, and then pronouncing all impressions, as parts of time, successive. A statement that ‘as from the coexistence of visual, and also of tactual, perceptions we receive the idea of extension, so from the succession of perceptions of every kind we form the idea of time,’ would arouse the suspicion of the most casual reader; while Hume’s version of the same,--‘as ’tis from the disposition of visible and tangible objects we receive the idea of space, so from the succession of ideas and impressions we form the idea of time’ [4]--has the full ring of empirical plausibility.
How Hume avoids appearance of identifying space with colour, and accounts for the abstraction of space. 249. So far we have been considering the composition of impressions generally, without special reference to extension. The contradiction pointed out arises from the confusion between impressions as felt and impressions as thought of; colour, between feelings as they are in themselves, presented successively in time, and feelings as determined by relation to the thinking subject, which takes them out of the flux of time and converts them into members of a permanent whole. It is in this form that the confusion is most apt to elude us. When the conceived object is one of which the qualities can really be felt, _e.g._ colour, we readily forget that a felt quality is no longer simply a feeling. But the case is different when the object is one, like extension, which forces on us the question whether its qualities can be felt, or presented in feeling, at all. A compound of impressions of colour, to adopt Hume’s phraseology, even if such composition were possible, would still be nothing else than an impression of colour. In more accurate language, the conception, which results from the action of thought upon feelings of colour, can only be a conception of colour. Is extension, then, the same as colour?
To say that it was would imply that geometry was a science of colour; and Hume, though ready enough to outrage ‘Metaphysics and School Divinity,’ always stops reverently short of direct offence to the mathematical sciences. As has been said above, of the three main questions about the idea of extension which his doctrine raises--Is it itself extended? Is it possible without reference to something other than a possible impression? Is it the same as the idea of colour or tangibility?--the last is the only one which he can scarcely even profess to answer in the affirmative. [1] Even when he has gone so far as to speak of the parts of a perception, a sound instinct compels him, instead of identifying the perception directly with extension, to speak of it as ‘affording through the situation of its parts the notion of’ extension. [2] In like manner, when he has asserted extension to be a compound of impressions, he avoids the proper consequence of the assertion by speaking of the component impressions as those, not of colour but, of coloured points, ‘atoms or corpuscles endowed with colour and solidity;’ and, again, does not call extension the compound of these simply, but the compound of them as ‘disposed in a certain manner.’
When the idea which is a copy of this impression has to be spoken of, the expression is varied again. It is an ‘idea of the coloured points _and of the manner of their appearance_,’ or of their ‘disposition.’ The disposition of the parts having been thus virtually distinguished from their colour, it is easy to suppose that, finding a likeness in the disposition of points under every unlikeness of their colour, ‘we omit the peculiarities of colour, as far as possible, and found an abstract idea merely on that disposition of points, or manner of appearance, in which they agree. Nay, even when the resemblance is carried beyond the objects of one sense, and the impressions of touch are found to be similar to those of sight in the disposition of their parts, this does not hinder the abstract idea from representing both on account of their resemblance’. [3] [1] Above, paragraph 233. Though, as we shall see, he does so in one passage. [2] Above, paragraph 235. [3] P. 341 [Book I, part II., sec. III.] In so doing, he implies that space is a relation, and a relation which is not a possible impression.
250. If words have any meaning, the above must imply that the disposition of points is at least a different idea from either colour or tangibility, however impossible it may be for us to experience it without one or other of the latter. Nor can we suppose that this impression, other than colour, is one that first results from the composition of colours, even if we admit that such composition could yield a result different from colour. According to Hume, the components of the compound impression are already impressions of coloured ‘points, atoms, or corpuscles,’ and such points imply just that limitation by mutual externality, which is already the disposition in question. Is this ‘disposition,’ then, an impression of sensation? If so, ‘through which of the senses is it received? If it be perceived by the eyes it must be a colour,’ &c. &c.; [1] but from colour, the impression with which Hume would have identified it if he could, he yet finds himself obliged virtually to distinguish it. It is a relation, and not even one of those relations, such as resemblance, which in Hume’s language, ‘depending on the nature of the impressions related,’ [2] may plausibly be reckoned to be themselves impressions.
The ‘disposition’ of parts and their ‘situation’ he uses interchangeably, and the situation of impressions he expressly opposes to their ‘nature’ [3]--that nature in respect of which all impressions, call them what we like, are ‘originally on the same footing’ with pain and pleasure. Consistently with this he pronounces the ‘external position’ of objects--their position as bodies external to each other and to our body--to be no datum of sense, no impression or idea, at all. [4] Our belief in it has to be accounted for as a complex result of ‘propensities to feign.’ How, then, can there be an impression of that which does not belong to the nature of any impression? What difference is there between ‘bodies’ and ‘corpuscles endowed with colour and solidity,’ that the outwardness of the latter to each other--also called their ‘distance’ from each, other [5]--should be an impression, while it is admitted that the same relation between ‘bodies’ cannot be so? [1] Above, paragraph 208. [2] P. 372 [Book I, part III., sec. I.], ‘Philosophical relations may be divided into two classes: into such as depend entirely on the ideas which we compare together; and such as may be changed without any change in the ideas. ... The relations of contiguity and distance between two objects may be changed without any change in the objects themselves or their ideas.’
251. To have plainly admitted that it was not an impression must have compelled Hume either to discard the ‘abstract idea’ with which geometry deals, or to admit the possibility of ideas other than ‘fainter impressions.’ It is a principle on which he insists with much emphasis and repetition, that whatever ‘objects,’ ‘impressions,’ or ‘ideas’ are distinguishable are also separable. [1] Now if there is an abstract idea of extension, it can scarcely be other than distinguishable, and consequently (according to Hume’s account of the relation of idea to impression) derived from a distinguishable and therefore separable impression. It would seem then that Hume cannot escape conviction of one of two inconsistencies; either that of supposing a separate impression of extension, which yet is not of the nature of any assignable sensation; or that of supposing an abstract idea of it in the absence of any such impression. We shall find that he does not directly face either horn of the dilemma, but evades both of them. He admits that ‘the ideas of space and time are no separate and distinct ideas, but merely those of the manner or order in which objects’ (_sc._ impressions) ‘exist’.
He denies that it is a separate impression, so far as that is necessary for avoiding the challenge to specify the sense through which it is received; he distinguishes it from a mere impression of sight, when it is necessary to avoid its simple identification with colour. By speaking of it as ‘the manner in which objects exist’--so long as he is not confronted with the declarations of the Fourth Book or with the question how, the objects being impressions, their order of existence can be at once that of succession in time and of co-existence in space--he gains the credit for it of being a datum of sight, yet so far distinct from colour as to be a possible ‘foundation for an abstract idea,’ representative also of objects not coloured at all but tangible. At the same time, if pressed with the question how it could be an impression of sight and yet not interchangeable with colour, he could put off the questioner by reminding him that he never made it a ‘separate or distinct impression, but one of the manner in which objects exist.’ [1] Pp. 319, 326, 332, 335, 518. [Book I, part I., sec. IV and VII, part II, sec. I, and part IV., sec. V.] [2] P. 346. [Book I, part II., sec. IV.] [3] P. 480. [Book I, part IV., sec. II.]
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